#include <iostream>

using namespace std;

int main()
{
	long long world;
	long long usa;
	double res;
	
	cout << "Enter the world's population: ";
	cin >> world;
	cout << "Enter the population of the US: ";
	cin >> usa;
	
	res = double(usa) / double(world);				// have to cast ...
	
	cout << "The population of the US is " << res * 100 << "% of the world population" << endl;
	
	return 0;
}